Customizing OpenShift JBoss confs without customizing the cartridge

I added a feature recently to enable OpenShift administrators to specify (at the broker) a custom location to get the default app git template from. This allows you to customize the initial experience of developers when they create an app; so you can, for example, put your organization’s name and logo on them. This should be out in Origin nightly builds now and the Enterprise 2.0.3 point release coming soon.

For JBoss applications, there is an added use for this feature. JBoss configuration files are located in the application git repository, so if you wanted to change the default confs for these cartridges as an administrator, say to add a custom valve, you can. Users are free to ignore this, of course, either by specifying a different source for their code or blowing your changes away after creating the app. Still, it can be useful to set the defaults the way you like, and with this feature, you don’t have to customize the cartridge to do it. You just need to maintain a custom git repository.

There’s a slight complication, though, as I discovered when trying to demonstrate this. The JBoss cartridges construct configuration files with three processing steps in between the source and the outcome. These are:

  1. The “install” step of cartridge instantiation modifies the Maven pom.xml that ships with the default template, replacing strategically-placed {APP_NAME} entries with the application name. If you construct your template using the source, Maven will not like it if you leave these as-is.
  2. The “setup” step of cartridge instantiation combines shared configuration files with version-specific configuration files from the cartridge source.
  3. Most of the conf files in the application git repo are directly symlinked from the actual gear configuration. However, there are a few that aren’t, which happen to be the ones you tend to want to change. These are actually templates that are processed during every build of the application (i.e. every git push).

These aren’t hard to work around, but they’re a little surprising if you don’t know about them. Let me demonstrate how I would do this with an example. Let’s say we wanted to change the log format on a JBoss EWS 2.0 cartridge.

  1. First, create an EWS 2.0 app with the installed default:
    • rhc app create template jbossews-2.0
  2. Now edit the resulting “template” directory that git creates as needed:
    • Change .openshift/config/server.xml log valve as follows:
      <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
             prefix="localhost_access_log." suffix=".txt"
             pattern="CHANGED %h %l %u %t &quot;%r&quot; %s %b" />
    • Note, this is one of the files that is interpreted with every git push. The Connector element has expressions in it which are evaluated at build time on the gear.
    • Edit the pom.xml file. This is optional, but you may want to use a different groupId, artifactId, etc. than just the “template” app name. It’s possible to use env vars here, e.g.
      <groupId>${env.OPENSHIFT_APP_DNS}</groupId>

      … however, Maven will give out WARNINGs with every build and threatens to break in the future if you do this, so I don’t recommend it.

    • Commit the changes.
       git commit -am "Template customizations"
  3. Now put this git repo somewhere all the nodes can see it. You can put it on github if you like, or your internal gitolite instance, or just on a plain web server. For simplicity, I just put it directly on the node filesystem, but remember that all nodes have to have the template available in the same place (although it could be useful to vary the template contents according to gear profile):
    # mkdir -p /etc/openshift/templates
    # git clone template /etc/openshift/templates/jbossews2.git
  4. Now modify the broker to specify this as the default. In /etc/openshift/broker.conf:
    DEFAULT_APP_TEMPLATES=jbossews-2.0|file:///etc/openshift/templates/jbossews2.git

    … and restart the broker:

    $ service openshift-broker restart

    Of course, with multiple brokers, you need to do this for all of them.

At this point, whenever you create a new jbossews-2.0 application, it will default to using your template and the changed access log format.

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Stuff that should just work…

Had one of those Maven/Eclipse experiences that was so infuriating, I need to record it here to make sure I can fix it easily next time.

Using STS 2.9.1 I created a “Dynamic Web Module” project. For the runtime I targeted tc Server / Tomcat 6. Then I proceeded to do some rudimentary JSP stuff, only to find that the JSTL taglibs were not resolving. It seems the expectation is that these would be provided by the container. Under JBoss they probably would be, but not under Tomcat. (I guess it makes sense… if you have multiple apps in the container, just let each one bundle the version desired – fewer container dependencies).

Fine; so I added the maven nature and the jstl.jar dependency. At some point I did Maven > Update project configuration. Suddenly the class that I had defined to back a form is not found. Also I’m getting this really annoying project error:

Dynamic Web Module 3.0 requires Java 1.6 or newer. [...] Maven WTP Configuration Problem
One or more constraints have not been satisfied.

WTF? Of course STS/Eclipse are configured to use Java 1.6… but my project apparently isn’t. So I go change that, but it doesn’t fix that error, and any time I update project config with Maven, it’s back to using JRE 1.5 and my Java source files are no longer on the build path as source files.

Turns out (took longer to find than to tell about it) the Maven compiler plugin doesn’t use Eclipse settings and just imposes its own defaults, i.e. Java 5, unless otherwise configured by a POM. And since a “Dynamic Web Project” uses Servlet 3.0 it requires Java 6. Boom.

Easy to fix, though annoying that I have to and there isn’t some Eclipse setting for this. Just add under the top-level POM:

<build>
    <plugins>
       <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>2.1</version>
          <configuration>
             <source>1.6</source>
             <target>1.6</target>
          </configuration>
       </plugin>
    </plugins>
 </build>

(Cripes, WordPress, can I get a “code” formatting/paste option already?? “Preformatted” most certainly isn’t.)

Then have Maven update project config again and 1.6 is in play. Oh, and instead of using the “src” directory for my source, I went ahead and changed to src/main/java as Maven expects, so that future “config update” will pick that up.

Checking out Hibernate with STS

I have cause to revisit my post about importing a git checkout into Eclipse. I need to take a look at the Hibernate code, which is on github at git://github.com/hibernate/hibernate-orm.git, and given the somewhat convoluted nature of this code, I need an IDE to help navigate it.

Now, I hear that with Eclipse Indigo (3.7), which is included with the latest STS 2.9 (which is what I use), the EGit plugin is included out of the box (which, for the purposes of this post, is what I’m doing – completely stock install). That’s helpful. See, previously, if you wanted to do something with git, you would find no evidence within Eclipse that it could. If you figured “there must be an extension for that” and searched for “git” from the extensions wizard, there would be no hits. Because what you needed to look for was “JGit” or “EGit” – you big dummy. An example of what I consider low discoverability that’s pervasive in Eclipse/STS. But I digress.

At least EGit has had a couple years to bake since my post. I went to File->Import->Git->Projects from Git and put in the URI above. This seems pretty straightforward:

Image

I’m not sure why it parses the URI into Host and Repository path here. Is there some reason you’d want to customize these?

In the next step, I pick the branches from the repo I want and proceed to the “local destination” dialog.

Image

These steps might be somewhat confusing to those who don’t know git and just want to take a look at some code. Since git is distributed, you don’t just get a point-in-time checkout from a repo, you get your own copy of the repo – or as much of it as you want. Basically it’s asking where I want my copy of the repository and checkout to go. The checkout (“initial branch” here) will go in the directory, and the repo will go in a .git subdirectory. “origin” is the name given to the repository I cloned this from, in case I want to sync with that later. That might be kind of obvious to someone familiar with git, but how about some tips for those who aren’t?

My question: why doesn’t this all simply default to being inside the workspace? What’s a workspace for, if not the project contents? As you can see, the default is to create a ~/git directory and checkout/clone the repo there.

Next step, three inscrutable options for how to deal with the resulting project(s) that have been checked out:

Image

OK. These seriously need some explanation. What do these do?

“Import existing projects” gets me nowhere in this case, as it requires Eclipse project descriptors to be included in the checkout, and they’re not. Arguably, they probably shouldn’t be. I just get the error “no projects found” if I try this. But that means I need to figure out myself how to get Eclipse/STS to interpret this checkout properly.

“Use the New Project wizard” is an option I don’t really understand. It just dumps you into the new project wizard you would get by clicking the new project button (generally the first button in the toolbar). This is also where you end up if you click “Finish” instead of “Next” anywhere along the way. I guess I could make use of the directory just created. I  also can’t go “back” and choose another option from here; cancel, and I’m back to square one. In general, I find the “New Project wizard” one of the most confusing things about Eclipse/STS, because there are so many options, many sounding similar yet meaning something completely different, and no explanations of what you can expect to get. Do I really have to go looking for doc that should be a click away? I digress.

“Import as general project” basically just creates a project with the given content and no organization. STS recognizes the different file types, of course, but there’s no concept of where the classpaths begin, how to build and test the project, anything like that – just plain directories with content. This won’t get me to my goal, which is to be able to look up class hierarchies, implementors of interfaces, etc. However, having done this, I can try to configure the project to get it to where STS understands these things.

I’m interested in the 3.6 branch of Hibernate, which is a Maven project (you can tell from the pom.xml – woe betide you in the Java world if you don’t recognize Maven when you see it. The “master” branch seems to be using Gradle). So I can right-click the project and Configure -> Convert to Maven Project.

By the way, let me point out something that didn’t work at all: creating a new project with the wizard “Maven -> Checkout Maven Projects from SCM”.

Image

This is apparently not aware of the EGit plugin, because there’s no SCM protocol listed here (the first box  is greyed out). If I click “Finish” here nothing happens except the dialog exits. I think it would probably work if I added a m2e SCM connector like the link suggests, but how would I know to do that?

Alright, so now I have a Maven project. Right away in the top-level pom.xml I get a “Project build error: Unresolveable build extension: Plugin org.jboss.maven.plugins:maven-jdocbook-style-plugin:2.0.0 or one of its dependencies could not be resolved: Could not find artifact org.jboss.maven.plugins:maven-jdocbook-style-plugin:jar:2.0.0 in central (http://repo1.maven.org/maven2)”. I happen to know what this is about because I know there are a bunch of JBoss dependencies not in Maven Central. How would I know that if I didn’t know? Google, I guess. Fortunately searching for that exact error message gets me right to a StackOverflow question about exactly the same thing, which someone has helpfully solved. I love SO, I just hate that it has to exist. Documentation is always about how to use something the right way, not what to do when something goes wrong. SO fills that gap.

So, add the repository information to the pom.xml – or, better, to my Maven settings.xml (which I had to create since STS is providing Maven in this setup) and on to the next problem. Two, actually (always seems to be the way of it – removing a build problem just uncovers more). These are related to “Missing artifact commons-logging”. A little Google sauce on that turns up this blog post (like the name, kinda like my blog!) about the death of the commons-logging dependency. Gotta love trying to support these old builds from a public ever-changing repo. Problem is, the Hibernate pom (actually the parent pom, which is in a subdirectory! huh?) uses the hack from that article, but the repo supplying the dummy dependencies seems to be down. So perhaps I should try the exclusions suggested by commentors in that blog? I found something that looks handy: in the pom dependency hierarchy, right-click and choose “Exclude Maven artifact”:

Image

Sadly, this doesn’t work:

Image

But here’s another StackOverflow suggestion. This seems to work, after removing the existing commons-logging dependencies and adding those ones in the parent pom, and (finally) right-clicking on the project, Maven -> Update project configuration. The errors are gone, and (I suspect) so is all the Maven-fu I can expect today.

Unfortunately I’m still not at my goal – I just have the Maven nature working now.

Turns out, this wasn’t quite the right path. What I’m looking at here are multiple Maven projects, with interdependencies. There’s no way I’m ever going to get anything useful from this in a single STS project. What I need to do is import these as multiple projects. In the meantime, delete the existing project (but leave the checkout) so it doesn’t get in the way.

So here’s what I do: File -> Import -> Existing Maven Projects and enter the path to my local checkout as the “Root Directory”:

If I select all the projects, they’ll all be created as interdependent workspace projects, each with build path and so forth configured according to Maven.

With lots of errors, of course… thousands, in fact. But let me start with the Maven problems, which are probably the source of the rest. Looks like all of the Maven errors are of the form “Plugin execution not covered by lifecycle configuration: org.jboss.maven.plugins:maven-injection-plugin:1.0.2:bytecode (execution: default, phase: compile)” – with a different plugin each time. I remember the import screen warned about some problems that would need to be resolved later – this seems to be what it was talking about.

Well, much later now, I think the Maven errors were mostly irrelevant. Those were due to the change to the m2eclipse plugin which broke the world for a lot of Maven users in Eclipse. Most of them were things that looked like it was safe to have m2eclipse “ignore” as recommended there. I went ahead and ran some of the goals that looked important (antrun:run and injection:bytecode in hibernate-entitymanager, the latter in hibernate-core) from the command line. Not sure they made much difference. I did Maven -> Update Project Configuration on everything changed and most of the red X’s went away.

I also ran into this problem and crashed a few times just by mousing over the “Window->Browser” menu before adding “-Dorg.eclipse.swt.browser.DefaultType=mozilla” to my STS.ini to avoid it.

At this point, the only problem seems to be that hibernate-entity has a ton of tests with imports like this:

import org.hibernate.ejb.metamodel.Customer_;
import org.hibernate.ejb.metamodel.Order;
import org.hibernate.ejb.metamodel.Order_;

… and then goes on to use these classes with underscores, which aren’t there. Evidently they’re supposed to be generated at some point, but I’m not sure how. I don’t really care about running these tests, just wanted to look at the framework code, so although STS reports 14382 Java problems, I can consider my work done here. Boy, that was easy!

One more note: I went back and added the git SCM connector for m2eclipse to try it out. It worked… but poorly. The way that worked was to select “git” for the scheme, then put in the git:// URI for the project, then wait for a popup to select the projects to import. If I reversed order or didn’t wait, I got either an error or nothing after hitting “Finish”. Hmm… hope that’s better in the next update. And, interestingly… the checkout/repo went into the workspace.

It’s not the errors that make me scream about Java/Maven/Spring/Eclipse

What really gets me is that I always seem to come up against ones that are not only inscrutable, but seem to be unique to me. Google brings up nothing, or brings up only irrelevant results from five years ago and a different context. Here’s my latest. In a Spring configuration file, I have:

<jdbc:embedded-database id="dataSource">
    <jdbc:script location="classpath:rewards/testdb/schema.sql"/>
    <jdbc:script location="classpath:rewards/testdb/test-data.sql"/>
 </jdbc:embedded-database>

This gets me an error in Eclipse (STS actually): “No constructor with 1 argument defined in class ‘org.springframework.jdbc.config.SortedResourcesFactoryBean'”

Huh?

Google’s not helpful. Looking at the source of SortedResourcesFactoryBean doesn’t display any evident source for the problem. Guess I’ll ask on the Spring forum and see if I can find out anything. For all I know it’s an STS bug with 2.5.1; this exact same code and setup worked before, in an earlier version of STS. But it’s probably something related to the environment, perhaps the JARs I happen to have available via Maven.

#maven screams

That is, it screams by proxy. Through me. All it does by itself is barf verbose output.

Let’s try the absolute first example. After apparently trying to download the internet, it works. But hey, what’s this I notice in the output?

[INFO] [archetype:create]
[WARNING] This goal is deprecated. Please use mvn archetype:generate instead

That’s encouraging. Let’s try this when I create another project.

[…]
242: remote -> flexmojos-archetypes-modular-webapp (null)
243: remote -> nexus-plugin-archetype (null)
244: remote -> spring-osgi-bundle-archetype (Spring OSGi Maven2 Archetype)
245: remote -> spring-ws-archetype (Spring Web Services Maven2 Archetype.)
246: remote -> trails-archetype (null)
247: remote -> trails-secure-archetype (null)
248: remote -> tynamo-archetype (null)
249: remote -> circumflex-archetype (null)
Choose a number: 58:

Wait, WTF is this? “Pick a number, any number!” I didn’t come to play guessing games, I just want to generate a project in the approved way. Apparently even that essential, obvious step is too complex to “just work”. And heaven help me if I cd into one of the project directories I’ve created and try another project creation command:

[ERROR] BUILD ERROR
[INFO] ————————————————————————
[INFO] Error creating from archetype

Embedded error: Unable to add module to the current project as it is not of packaging type ‘pom’

Well, you know what they say. Clear as mud.

Yes, I’m being deliberately obtuse. I can figure out what’s going on here. But come on; this is ridiculous. Isn’t maven supposed to simplify things? Doesn’t simple mean that for common things, it works as expected and gives feedback that a normal human being can make sense of?